MUSEUM OF THE NATURAL HISTORY SOCIETY. 277 



Scar Limestone Series. — From the position of the Great 

 Whin Sill in the Alston Moor district to the lowest bed of Car- 

 boniferous limestone. It is composed, like the former series, of 

 several beds of encrinital limestone, some of which are locally 

 of great thickness (Melmerby Scar limestone is sometimes 

 120 feet), interstratified with beds of crystalline sandstone and 

 shale, and a bed or two of coal. Between the North Tyne and 

 the Tweed, in the lower part of this series, the beds of coal 

 become more frequent, thicker, and of better quality than in the 

 Pennine escarpment, and the limestones are thinner, impure, 

 and deteriorated, and thick beds of grit and sandstone predomi- 

 nate. In the lower part of this series the Plashetts and 

 Scremerston coal beds are situated. 



Some of the land plants are perhaps identical with species 

 belonging to the above division, with others quite distinct. 

 Most of the marine fossils are also identical, but several of those 

 in the following list are unknown in the higher beds : — 



It crops out along the base of the Pennine range in its exten- 

 sion northwards till the escarpment of the latter is thrown down 

 by the Stublick dyke. Thence it occupies the western part of 

 Northumberland from the outcrop of the Yoredale beds nearly 

 to the foot of the Cheviot range. Good sections may be seen in 

 the burns and smaller valleys of the North Tyne and Coquet, 

 and at the base of the Pennine escarpment as near Dufton in 

 "Westmoreland, where the following sections of this series may 

 be observed : — 



Pnij. ft. 



GREAT WHIN SILL 10 



Plate 3 



Hazle 2 



Plate 2 



Hazle 3 



Plate 1 1 



Limestone (Jew) 3 



Plate 1 



Hazle 5 



Plate 1 1 



Limestone (Little) 1 



Hazle 1 1 



Fms. ft. 



Great hazle 10 



Plate 4 



Limestone (Smiddy) 4 1 



Hazle 1 



Limestone 4 1 



Hazle 1 



Limestone 3 



Plate 1 1 



Limestone 1 l 



Plate 1 1 



Great Limestone (Robin- 

 son's) 14 



